Electrochemical sensors are known, which are applied, for example, for monitoring the production of sulfuric acid. In order that such a sensor can deliver correct measured values, it must be calibrated and/or adjusted. “Calibrating” refers, in such case, usually, to the determining of a deviation of the measured value measured by the sensor from the correct, measured value, while “adjusting” refers, usually, to the correcting of the measured value measured by the sensor to the correct, measured value. This calibrating and/or adjusting is, in the case of known sensors, put into practice by first installing the sensors at their measuring locations, so that they can then be calibrated and/or adjusted there. Clearly, such on-site calibrating and/or adjusting are/is connected with considerable effort.
Furthermore, most often, a plurality of sensors are in use in such a production plant, wherein, in the case of a defect in one of the sensors, frequently, an immediate replacement of the defective sensor is required. For this purpose, most often, a plurality of new and/or used sensors are stored, in order to assure a fast replacement. This large number of sensors, as well as the different types of the sensors, introduces the risk, that, especially in the case of an immediately required replacement, a sensor is installed, which is not the correct replacement-sensor, but, instead, for example, an incorrect sensor type.